Dungeon

A Dungeon is an artificially constructed Cave (though this means it's purpose-built, not by the player, but from World Seed generation). They contain Spawners, which spawn hostile Mobs and must either be destroyed or lit up to neutralize their threat.

Dungeons are always cube-shaped, and are denoted by their walls, which are formed from Mossy Cobblestone. This material cannot be found elsewhere in the game.

In more recent versions of Minecraft, dungeons have pre-generated Chests with uncommon or rare items within them. Hostile Mobs also inhabit dungeons. Dungeons are also a great way to collect Experience Orbs because there are always mob spawners within them, enabling players both to build mob traps and kill monsters in a relatively controlled environment.